Granted Patent
Utility
US 5,638,440 · App. 08/487,999
Protection circuit for telephone systems
Inventors:
Michael A. Nix, Walter S. Schopfer, Sergio R. Ramirez
Patented Case
View Patent ↗
Granted: Jun 10, 1997
Filed: Jun 7, 1995
Inventors
Michael A. Nix
Walter S. Schopfer
Sergio R. Ramirez
Assignee (at issue)
Advanced Micro Devices, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.